I would have to make a point about fans. If your room temp is 90-100 then your fans are blowing 90-100 degree air. It can certainly help air circulation. Evaporation will occur no matter what - it is just what prevents it from escaping into the open air of your kitchen (i.e. like glass canopy or full hood.
depending on how big your tank is (I don't recall) 2 liter frozen bottles is a good idea but I suggest those 20oz soda bottles (10 or more so they spread around) or those plastic quart containers (or even those quart juice or milk cartons where you freeze aged or conditioned water, then plop 6-8 in your tank direct so it melts & refill the containers to freeze again.
I have had pretty good results (about 3-5 degree drops). the larger the tank & surface volume the more chunks you need to put in. they will act like icebergs, albeit melting fast bergs!
maybe a combo ice plops (large chunks as ice cubes do nothing) & cold cold airline tubing shooting kool air thru the air diffuser - now that's a DIY'er plan!
good luck
this is the best DIY method.
the freezing blue ice packs & airtube sounds like a neat idea also.